For a long time drilling has been combined with the farmer simultaneously laying down fertiliser and possibly one or more other chemical compounds in the soil. The seeds are laid down with a seed drill or more often in this context with a precision seed drill or planter. In the following the implement is referred to by the American term planter, which is also an accepted term in the rest of the world.
A planter sows or sets seeds of crops such as maize, sugarbeet, cotton, sunflower etc. in seed rows which lie at a distance from each other commonly of approx. 20 to approx. 100 cm. The individual seeds are placed in the seed rows at a distance that is commonly 10-20 cm from each other, meaning that approx. 10-20 seeds are fed out per second from each of the constituent so-called row entities in the planter. The fertiliser is sometimes placed directly in the seed row, which poses a risk since the fertiliser and then particularly the nitrogen (N) tend to scorch the little seedling that grows out, wherein the plant dies or is weakened. It is often better to lay the fertiliser in a separate row that is usually laid approx. 5 cm from the seed row. The fertiliser can well be placed a few cm deeper than the seed. The seed, for example maize grains, is usually placed at approx. 5 cm depth. For different crops different predetermined sowing depths apply. Climate zones, different regions, seasons, weather conditions, soil type etc. can also affect the choice of sowing depth. Chemical compounds to prevent different plant diseases, combat pests or weeds etc. can also be laid out at sowing. These chemical compounds are often placed in the seed row, sometimes above the soil surface, depending on the aim of the treatment. How common this is depends on many factors such as amount of weeds, infections in the soil, climate zone conditions etc. The compounds applied can be dry and granular, in powder form or in liquid form. In certain regions, for example in North America, liquid or gaseous (gasified liquid ammonia) fertiliser is used on a large scale.
It is often a waste and unnecessary environmental impact to lay fertiliser and/or one or several chemicals in an uninterrupted row or string since there is approx. 20 cm between every seed. This also leads to nutrients being unnecessarily accessible to weeds.